Traffic signaling system



y 1941. P. P. HORN! 2,240,848

TRAFFIC sIGNALING SYSTEM I Original Filed July 9, 1937 7f 7 77/ i 73 BBEEEEB 9/ Flg. 1

and 99 (73 H a; ,1:

LIGH TS HIGHWAY CROSS ST. 1

OPERATES INVENTOR I l m TORNEY Fi 3 P/IUL R HORN! Patented May 6, 1941 UNITED STATES PATENT OFFIQE TRAFFIC SIGNALING SYSTEM Paul P. Horni, Newark, N. J.

Original application July 9, 1937, Serial No.

152,772. Divided and this application May 8, 1939, Serial No. 272,438

Claims.

tem of the automatic type the signals of which are subject to control by trafiic which may be either pedestrian or vehicular, and is a division of my pending application Serial Number 152,772 filed July 9, 1937, now Patent Number 2,157,236 issued May 9, 1939.

Since the flow of traffic usually has a greater density on one street than on an intersecting street, it is necessary to allot more time to the street having the more dense tranic flow to expedite vehicular movement and allay congestion.

It is well recognized among traffic engineers that V to unnecessarily change the signal lights by indicating a go signal to a cross-street to be benefitted thereby, and at the same time set up a stop signal to the busy main street, is to aggravate traific congestion and invite accident. This undesirable feature may be avoided by provicling a discretionary signal control operable by trafiic on the cross street of an intersection. It is particularly desirable to have this traffic control feature on a side-street which has only occasional traffic. In this way, traffic can flow uninterruptedly until a demand is made by a vehicle on the side-street. Traflic signals are fregueiitly installed to take care of such occasional ra c.

It is likewise desirous under certain conditions to indicate neither a definite stop nor go signal on either street unless a side-street vehicle has demanded the right to cross the intersection by actuating an initiating device. The absence of lights, unless required for traflic control, is a great saving in power consumption over the continuously operated typeof trafiic control system, reduces the cost for electric light bulbs, since fewer replacements are necessary, curtails labor expense for replacement of the burned out bulbs, eliminates muchrepair work by prolonging the life of the controller, and reduces the percentage of potential accident periods due to an unsupervised intersection, caused by burned out trafiic signal bulbs.

To supervise an intersection which utilizes a trafiic control system having the signal lights normally extinguished on both the main and the cross-street, it is necessary to provide devices which may be operated by the traffic to control the signals. These devices which are operated by traffic to initiate a signaling cycle with the equipment present in this application, may be operated by a vehicle or a person It will be noted that means are provided, for cross-street, surface or trolley cars, as well as automobileato This invention relates toa trafiic control sys- 'f initiate a signaling cycle.

The vehicle actuated 1 initiating means, whether mechanical or magnetic, are commonly referred to in the art as detectors.

Applicant's copending application, Serial No. 484,334 is to be distinguished in part from the instant case which has definite and distinct advantages and improvement thereover.

When traffic is active along a main street, which is controlled by normally extinguished trafiic signals, experience shows that it is inadvisable to suddenly present a stop signal to the To do so, would result in numerous rear end collisions of the vehicles. Consequently, it is expedient to present to moving trafiic, a warning or caution indication, prior to displaying a stop signal. This gives the traffic an opportunity to adjust itself to the realization that a traffic signal is ahead. While a warning signal is beneficial in the normally extinguished type of traffic signal, it is recognized that the benefits of the warning or caution signal has its limitations, since it attracts the attention of the Vehicle driver, but indicates no definite signal.

It is accordingly a primary object of this invention to provide a traffic signal control system of the automatic type which has its operation initiated by traffic demand, to cause at least one signal cycle, which indicates go to the moving traflic and stop to the cross-street traffic, for a brief interval, then to continue through its normal cycle, part of which cycle indicates go to a side street and stop to the main or intersecting street, then changes to again indicate go to the highway and stop to the crossstreet, and shortly thereafter, if no demand is made on the cross-street, to lapse into inactivity, giving no signal light in any direction and thereby permitting the regular uninterrupted flow of traific on the main street, until a future demand is made by a cross-street vehicle or a pedestrian.

The main street, at the intersection, is frequently of such width that it would require many seconds for a pedestrian to negotiate the distance. This lengthy exposure to moving traffic, subjects the pedestrian to a greater danger than if the street were quite narrow. To obviate this hazard, it is provided in this application, and made an object thereof, to allow a greater signaling supervised time for a pedestrian to cross the main highway, than for a vehicle, the shorter vehicle interval, and the longer pedestrian interval, each being initiated by a single independerated and again prepared for deceleration by further actuation of the cross-street traffic up to the completion of the cross-street green interval.

A further object is to provide asignaling system of the character indicated herein, in which the signaling cycle actuating motor is provided with two windings, one a forward and the other a reversing motor Winding, each tending to. turn the motor in opposite directions, and being of different torque so that when both windings are energized, the resultant torque on the motor shaft is'in a clock-wise direction and when the reversing winding circuit is open, the motor is accelerated, and when. the driving winding circuit is open, the shaft motion tends to reverse, in order to properly align the various circuit control cams upon completionv of a signal cycle, preparatory to future operations.

A'further object of the invention is to provide a traffic actuated signaling system, of the class described wherein the flow of traffic on the crossstreet causes a memory device to become oper-,

ated during the latter part of a signaling cycle to compel a new signaling cycle to become initiated and thereafter to have the traffic signals lapse into inactivity.

Another object is to provide a signaling sysv, tem wherein a vehicle passing over a detector initiates a signal cycle, a part of which indicates go on the street of actuation and stop on the intersecting street, said go signal being existant for a predetermined interval of time;

While a few of the objectsof' this invention have been definitely set forth, other and further objects and advantages of the invention will be hereinafter presented and the more. novel features thereof defined. by the appended claims.

A further object of this novel inventionisto provide a. signaling system in which a'vehicle passing over a detector may initiate a signal cycle a part of which indicates go on the crossstreet, said go interval being enlargeable up to a practical maximum.

For a better understanding of the invention, reference may be had to the accompanying drawing, in which:

Figure 1 is a schematic diagram of the circuit and representative mechanical parts utilized in this invention.

Figure 2 discloses a chart to indicate conditions. of contact operating cams and signaling lights at several different intervals of a signal cycle.

Figure 3 is a View generally representative of the positions of the cams and their respective cam rider members and associated contacts in a normal position.

The chart in Figure 2 can be better comprehended by associating same with Figure 3. In the latter figure, cams I and 3 areshown with the pivotal cam rider in an inoperatedor. reased position, that is, the. cam riders are .urged toward the center of the cam. While any means may be used to hold the cam riders against the peripheral surface of the cams, a coil spring 8,

operated. While cam 1 is indicated as being operated, the chart represents that it is not, in

fact, operated, but it may be, without altering the operation or effect of the system. The description, of operation will bring out that cam 1 contacts are ineffective until cam 3 contacts are closed-,which permits the cam I contact to be operated anytime prior to the closure of cam 3 contact.

, Signaling circuits The wiring diagram shown in Figure 1 has two conductors indicated by black. heavy lines which are marked Withaminus and. plus or negative and positive symbol to. denote simply a source of power, The several cams, shown in Figure 3 and numbered from I to l inclusive, havecentrally pivotedcam riders which have one end thereof normally urged against, thev riding surfaces ofthe various cams.v The opposite ends of the cam riders, have either one or, two contacts thereon to engage cooperative contacts. the functions of which will be more definitely explained in presenting the operation of the system.

In Figure 1, the cams are numbered as in Figure 3, and are shown schematically as a numbored, circle having a movable arm electrically connected thereto. When the switch 9 is moved ,to engage contact 1-9, a circuit isv traced from negative battery, through conductor l2, contact H1, switch 9,,conductors i3 and: M, cam arm 4A, contact I 6 and cam arm 2A. The circuit-is divided here and one branch goes: through contact 11., signal light G1 (highway green) conductor 30, to. positive battery, The other side. goes to R2, (cross-street red") conductor 31:, to positive battery. Since cams Z and 4 arenormally shown in an operated position when the signaling apparatus is idle, it will be seen that with switch set 9-.|9 closed, the lights would indicatea green or go sign al to the highway, or number 1 street, anda. red or stop signal to; the cross- ,street or numberZ street. GI AI andRl represent the green, amber and red lights respectively on the highway, while G2, A2 and; R2 represent green, amber and red' lights: respectively on the crossstreet-. In this condition with, the 9-40 contacts closed, the system would be said to have a normal highway. green.

When the signaling control. apparatus is set in operation from an: actuation by a cross-street vehiclegthe motor M rotates. Suitable gearing isprovided between the motor andtthe; cam shaft 18 which has securely fastened thereto, cams I to inclusive. For purpose of explanation, an arrow pointing in a clockwise direction, is,indicated to, the, left of cam I in Figure 3; After the GI and R2 lights have-been energizedsubsequent to an initiating; actuation, thecam; shaft reaches an interval. which causes cam arm 2A- to restore. and engage contact I 9 which energizes A] through conductors Z0 and 2|. Thev completion of thiscircuit causes A! and, R2 to be lighted as. represented in position 2. A continued rotation of shaft I8 causes cam 1 to operate, at the latest, just prior to the operation of cam 3. In position 3, cam arm 4A restores to open circuits to AI and R2 and to energize RI through cam arm 3A, contacts 32, conductors 22 and. 23, and

energize G2 through cam arm IA, contact 24, I

conductors 25 and 26, both toconnect to positive battery. At this time the cross-street green and highway red lights are energized. A continued rotation brings the cam to position 4, in which cam arm IA has restored, which deenergizes G2 and energizes A2 through cam arm IA, contact 21, conductors 28 and29, to positive battery, In position it will be seen that cam 3 has restored to break the signaling circuit to RI and A2, sub stantially simultaneously therewith, cams 2 and 4 operate to again energize GI and R2.

In position 4, cam 2 operates prior to beginning of period 5 so that the R2 and GI lights come on together. In the position 2, cam I operates prior to beginning of position 3 so that RI and G2 lights will also come on together. Cams 2 and I in positions ,4. and 2 respectively, show the latest period of operation to prepare the cam contact for simultaneous operation of the red and green light. The earliest time for cam 2 to operate is just after beginning of period 3, as cam 4 is open. The earliest time for cam I to operate is just after beginning of period 5, since at this interval cam 3 is open.

The operation explained immediately above shows the several signaling circuits when the contact set 9I0 is closed with the lights normally having a highway green and a cross-street red. If the switch 9 engages contact II, it will be noticed the conductor to the negative side of the battery is open. Consequently no current can flow to the lights when the apparatus is idle, yet the lights are prepared for operation through cam arms 2A and 4A, so that the GI and R2 lights will be energized as soon as a signaling cycle is initiated by traffic. The system would be said, under this condition, to be a normal ou as used in the field, since no lights are energized yet the intersection is protected and highway trafiic may move unobstructed. Immediately l upon demand, by pedestrian or cross-street traific, the operation of the system energizes the GI and R2 lights, and causes the system to move through its cycle, previously explained, permitting crossstreet traffic to control the intersection for a time interval, and then to change the lights in order to restart the highway traifice and stop the crossstreet trafiic. After the lights have been burning in this position, the signaling system stops its signaling cycle and the lights are extinguished, restoring the system to its "normal out condition preparatory for further actuation.

Single vehicle actuation The motor used in the signaling system, has two sets of windings, one set being a driving winding indicated as D which winding rotates the mechanism forwardly, the other winding is for reversing the motor when the driving winding, indicated as R is disconnected, and is used for retarding the forward motion of the motor when both windings are connected. Each set of windings consists of a U shaped group of laminations provided with a main winding and an E shaped group of laminations provided with a phasing winding. These phasing windings are represented in the drawing as P and P". The relation between the main and phasing windings is the same as that employed in the single phase AC watthour meters. The shaft 32 carries a disc 33 which I'revolves intermediate the main and phasing windings. In order to obtain a good driving torque, the main winding is connected in series with the phasing winding and said main windings each being by-passed by a condenser which causes the current through the phasing winding to lead the current through the main winding. The reversing winding is connected with the phasing winding in the same relative polarity of the driving winding, but the main winding of the reversing motor is poled oppositely to the main winding of the driving motor and therefore produces a torque tending to drive the disc in the opposite direction. In order to obtain a smaller torque from the reversing motor than from the driving motor, the capacitor 34 of the reversing winding is of a smaller value of capacitance than the capacitor 35 of the driving winding. The phasing windings are assembled in a common mounting with respect to their main winding and movable about the shaft 32, in axial relation thereto. This permits the simultaneous changing of the motor speed of both the driving and reversing windings. The entire motor is represented by a rectangular dotted enclosure indicated as M.

A single vehicle detector which may be of any convenient type, either magnetic or mechanical, issimply represented by two members 3636, but it is to be understood that this single detector may be parallel by another detector to take care of traffic on the opposing side of an intersection of a cross-street. It is apparent that the function of the system will be unchanged by using a plurality of detectors connected in parallel. When switch blades 9 and 37 are moved to the right by means of the connecting insulation strip, 38, shown dotted, contact set 9I0 would be closed to energize GI and R2. The circuit to the reversing motor would then be broken, by the switch blade 31 having moved ofi its contact which associates itself with the reversing winding of the motor. In this condition, there is a light normally green on the highway. When a vehicle moves over the detector to close the contacts 35-36, a circuit may be traced from negative battery through 38, 35-36, 39, contact 45, switch 4 I, conductor 42, winding of memory relay M, 55, to positive battery. Relay M is energized and draws in its armatures 43 and 44, which armatures now engage 43 and 44' respectively.

After the memory relay is energized, a stick circuit is completed for the relay M, and may be traced from negative battery, through 45, armature 44, contact 44', conductor 46, an armature 41 of relay E, and its associated contact 48, conductors 49, 42, winding of relay M, conductor 50, to positive battery. 7

When the armature 43 of the memory relay M is energized, the circuit between 43 and 43' is broken which circuit normally energizes the reversing motor over conductor 5| switch blade 52', contacts II and 53, and the cam arm IA, conductor 54, through the windings of R and P, conductor 55 back to positive battery. The negative battery is normally fed to the armature 43 over conductor 45. The negative battery which is normally on armature 43 of memory relay M is now engaging 43" and a circuit may be traced from negative battery over conductor 45, armature 43, contact 43", conductors 5B'and 57, to the driving Winding D of the motor, coil P, conductor 58 to positive battery.

The motor now having no eiiect from the reversing winding, can move forward freely and.

through suitable gearing, causes the cam shaft and its associated cams to: be rotated, starting the lights which move: through. the various steps of the signaling cycle. Cam 1, according. to the chart, may open shortly after the motorstarts to rotate, but since contact set t3,v 43" is open, a further opening of the cam arm IA can have no effect on the reversing winding of the motor.

' As No. I cam operates, opening the !A-53i conlB59, conductors 61,162, 6.3, 51-, windingsD and P, conductor 58 to positive battery. This. in-

sures the motor to run as long as thisv cam I is operated and: protects it from stopping, due to opening of the memory relay energizing circuit and the consequent opening of the armature 43 and its associated contact 43.

Cam arm 6A is indicated in the chart as being operated but itwill be notedthat this cam when operated, has its associated contact normally open. The cam arm A and its associated contact opens momentarily, that is, the cam 5 is operated periodically. Sometime after the G2 lightshave been energized, with the consequent energization of relay E, since G2 and relay E are in parallel, the armature 4'! of relay E will be drawn in, which opens the memory relay stick circuit contact set 41-48. The first of the periodic openings of cam arm 5A from its associated contacts, will positively open the circuit to the memory relay to deenergize same. obvious since it is apparent that the cam arm EA will control the energization of relay M for a short time-after the opening of the relay E eontact set 4'i43. A further actuation of thedetector 3636' would have noefi'ect upon the signaling'circuits since the momentary energize.- tion of the memory relay could not be locked in, since the other possible current paths are open at this instant. Furthermore, the 43-43 contact set, which controls the reversi-ng winding of 'the motor at certain times, is not controllable bythis contact set at this instant, since the lA--53 contact set is open, due to the operation of cam I, consequently the motor will run at its normal speed without the eiiectof thereversing winding until the end of the cycle, when the cam I releases'to break the energizing circuit or the driving windings to the motor, through the controlling contacts lB-59. When the cam l releases to cause deenergization of the driving winding, it causes contact set lA-53 to be closed, which now energizes the reversing winding of the motor, since the only other possible controlling contacts 4343', are closed.

The end of the cycle having beenreached and the green light returned to the highway to-indicate a go signal thereon, said signal will remain there, assuming the controlling contact set 9|B is still closed. The reversing winding will control the motor and start it to operate in a reverse direction but since the ratchet which is suitably geared to the motor gear train, has a pivotally mounted pawl 65: associated with said ratchet in such a way that thepawl will engage theratchet shortly after the reversing motor becomes effective, at the completion of the. signaling cycle, the effect. of f the reversing winding will be merely to rotate the motor in a reverse direction until the. ratchet: 6.4 is. positively gripped. by the pawl 65 to prevent further rotation. The

This is purpose of this: ratchet and pawl is to insure the cam shaft. I8 of a positive stoppin position. The definiteness of this stopping position, is of prime importance when the signal is operating with the lights normally out, because the starting position of the cams which. control the highway green and the. cross-street red lights, will determine the duration of. the burning of these lights before. they change to indicate a difierent signal.

The necessity of this precision of cam positioning at the termination of a cycle with the lights normally deenergized can. be shown by stating that in practice, when utilizing the normally out system, drivers of vehicles become accustomed to the length of time that the stop indication is presented to the cross-street before it changes to give them a go signal. Consequently, the driver familiar with the intersection will adjust the speed of his vehicle so that he may reach the beginning of the intersection just as the light changes, without the necessity of bringing his vehicle to a full stop,'thereby, maintaining the maximum efiiciency of speed. If the cam positioning'is such that the driver gets the go signalon the cross-street before he expects it, there may be no disastrous result, but experience has shown that if he should have the red light stay on the cross-street materially longer than usual, he may, in anticipation of receiving the go signal, permit his car to run out into the intersection while trafiic 0n the highway which usually travels at a high rate of speed, is attempting to clear the intersection.

It seems needless to say, that many serious accidents have been caused by drivers running into intersections-because of this feature of speed against time. While it is true the operator of a vehicle may wrongly estimate his speed, it is nevertheless alsotrue that drivers do depend on this timing of traific signals and a serious accident might beavoided, or a life preserved, by permitting a driver to have the proper precise timing that he has a right to expect.

M otor retardation during cross street interval When there is demand on a side street and only one vehicle crosses the intersection, the driving winding only controls the forward motion of the motor. However, when there are several vehicles, which crossduring the green period, there maybe more than one effective actuation of the detector. These additional efiective actuations cause the reversing winding of themotor to be periodically cut in to periodically have its retarding effect upon the torque of the motor shaft which consequently causes the motor to be slowed down and hold the go signal on the cross-street a little longer than the alloted time for a single vehicle to cross the intersection.

Earlier in the application", the'operation has been set forth'relative to the various circuits necessary for operation by the single vehicle, which single vehicle control was made possible by the switch 3-! being moved to the right and opening the circuit to the reversing motor by disassociati-ng switch 3 with the contact 66 of conductor 54-. The starting of the signal cycle which has been previously explained, is the same for a single vehicle. As soonas the cross-street green, or G2 lights are energized, the relay E is simultaneously energized, which moves the armature 41 against contact 61, which feeds negative battery to the reversing winding of the motor. The cireuitmay be: traced from the negative batteryover conductor 45; armature 44, con-1 tact 44, conductor ,46, armature, contact 61, conductor 68, contact 31-66, conductor 54, R and P", conductor 55 to positive battery. Immediately upon energization of the reversing winding, its consequent effect :is. to retard the revolutions per minute of the motor. Since the stick circuit over the controlling contact set 41-48 is broken, the stick circuit is now only controlled by the cam arm A and its associated contact. As previously explained, the duration of the opening of contacts controlled by cam 5, is periodic, and only open long enough to permit the memory relay M to become deenergized. As soon as the memory relay is deenergized, due to the opening of the 5A cam arm and its associated contact, the contact -set 4444' is open which causes the current flowing over the conductor 46, contact set 41-6'|, 68, 31, 66, 54, to the reversing winding, to be interrupted. This permits the motor to move under the influence of the driving winding only and to. assume its normal speed. Further actuations of the detector by a vehicle will cause the memory relay to operate, which slows down the motor and causes said memory relay to be released'upon the momentary opening of the stick circuit through cam 5A.

In the chart, in position 3, under cam 6, it will benoted that there is an interval for the latter part of said three position which overlaps into the beginning of position 4 in which cam 6 is not operated. When cam 6 is not operated, the contact 6A is in the positionishown dotted, which engages the contact associated with said camarm, and positively closes: the stick-circuit of the memory relay. When cam arm 6A is thus associated with its contact, it will'be observed that further periodic openings of the cam 5 will have absolutely no efiect upon the stick circuit. The memory relay will be locked in, consequently, beyond the control of the periodic openings of the 5A cam arm and its associated contact.

In position 3, the latter part of said position finds cam 6 released, which period is known as the memory interval, which interval is that portion of the total memory period which is included in the cross-street green period. The total memory period is that portion of the cycle be-v ginning with the last releasing of the memory relay, and terminating with the end of the cycle.

In position 4, cam 6 is released during thebeginning of the cycle, which release interval indi-' cates the released time allotted for the relay E.

At the beginning of period 4, cam 'l'releases which opens contact sets 1A--24 and transfers lights from G2 to A2. The relay E is thereby released, closing contact set ll-48, further rendering cam 5 ineffective. After 'the extension relay has had time to' release, the cam 6 may again operate which separates cam arm BA from its associated contact, thereby permitting the memory relay to be no longer under the control ofCam 6, during the remainder of the cycle.

An actuation during memory interval, or the total memory period will cause an additional revolution of the cam shaft and a corresponding signaling cycle, since the memory relay will be locked in to keep the contact set 4343" closed putting negative battery over conductor 45 on to conductors 56 and 51, to the driving motor, causing it to run irrespective of the condition of cam l and its associated contact set IB-59.

Continuous Operation independent of vehicle actuation Heretofore, the apparatus has been described as operating as a vehicle actuated system, but this is not necessary since by simply moving a double pole, double throw switch, to another position than that previously described, it is possible to have the system operate continuously and alternate the go signal and the corresponding stop signal with its intermediate caution periods from one street to the other, in a chain of connected signaling cycles. Two switches, 52 and 4| ,may be connected by an insulating member shown dotted as 69, which member may be moved to the right so that the switch blade M will 'be disconnected from contact 40 and the switch blade 52'wi1l be moved from the contact which is associated with 53 and said 52 blade will then be engaging contact 10. The circuit from all of the detectors which leads in to conductor 39 can no longer operate the memory relay. The switch 52, and its contact H, now having been broken to open the circuit, to the reversing winding, and when switch 52 is moved to contact 1!), battery is fed directly to the driving winding of the motor. In this respect a circuit may be traced from negative battery, over conductor 45, armature 43, contact 43', conductor 5|, contact-set 52-18, conductors 62, 63, 51 to driving winding of the motor, conductor 58 to positive battery. It will thus be seen that since no vehicle actuations can ever affect the signaling apparatus and since the motor is continuously operated forwardly at one speed, the cam shaft will continuously rotate and in turn, cause the lights to be transferred from one position to another in their proper sequential relationship, to

.enable traflic to move orderly.

Operation by surface car A pair of contacts '|2'l2' are shown in parallel with the contact set 3636, both sets of contacts, when closed, connecting negative battery to conductor 39, the contact set 12--'l2' is used to control the signaling system by a surface car 13. In operation, a shoe may be provided above the trolley wire, so that a passing surface car will engage that shoe to operate the signaling system.

These shoes may be provided on opposite sides of the cross-street so that a trolley car coming from either direction, may operate the signal if this is desirable. In any case, it will be understood that .1 any pair of contacts which are connected between negative battery and the conductor 39, will, at the proper time, control the signaling system. When a surface car wishes to cross the intersection, the trolley wheel proper, 15, will engage the shoe l4 .1 which completes the circuit. When the surface car contacts ll-J5 are closed, circuit may be traced from the source of energy 95, over conductor ll, through the contact-set ls-15, to conductor 16, resistor 8|, conductor 86, relay 19,

conductor 18, to the rails 9| upon which the surface car rides, back to the other side of the energy source. A ground is shown connected to the rails in Fig. 1. The resistor 8! may be located at any convenient place and may be of such value that when utilized in conjunction with the suitable relay 19, the resistor will limit the current flow to permit proper operation of the relay 19, to actuate the armature I2, to initiate a signal cycle.

While a specific arrangement is shown for the operation of the contact set 12-12, it is to be understood that any arrangement of parts may be used to ultimately cause a pair of contacts to be operated, which operation causes the initiation of a signaling cycle.

' few seconds.

Pedestrian control pressed by the pedestrian, a circuit is closedacross the contacts Bl-Sl', which puts negative battery on the winding of thecoil TD and energizes same by getting positive battery over the conductor 82. The energization of the relay TD will attract the armature 83, associated with contact 84. Said contacts being in parallel with the detector 31-456, and trolley contact 1212. It will thus be seen that the attraction of 83 which engages contact 84 will close the circuit from negative battery to conductor 39, thereby initiating a signaling cycle. Relay TD will also attract armature 86, which engages contact 85, whereby a stick circuit for the relay TD will be traced from the negative battery over conductor 89, contact set BL-B8, a second contact set 8586, winding of TD, conductor 82, back to positive battery. This circuit will hold contacts 83-84 closed for a period of time depending on the time required for the relay TD to release, said relay TD being a time delay relay, which has a releasing time required for two operations of the .cam 5. Relay Y is a restoring relay which unlocks relay TD, by interrupting the stick circuit due to the opening of the contact set 8l88, the armature 81 being responsive .to energization of relay Y, is same as operated at the beginning of the cross-street green, or G2 period, and allows relay TD to respond to each impulse caused by closure of contact set SI-8! of push button P. This special pedestrian control circuit is utilized, since it is conventional to provide simply an initiating button parallel to the detector. "It has been found in practice, that the time allowed for a vehicle to cross at theihtersectionfis frequently suificient for a pedestrian to cross at the intersection, when the initiating contacts *for the vehicle and pedestrian control are in parallel. This is permissive because the variation in time between that required by the vehicle and the pedestrian at the intersection, is usually just a However, many intersections are so wide that the time discrepancy will vary 'from to 20 seconds. The time delay relay, therefore, must be able to hold the 83'34 contact set'closed for a time greater than that between two impulses of the 5A cam arm.

While specific details of the system have been herein shown and described, the invention isnot confined thereto as changes and alterations may be and may become apparent to those skilled in the art without departing from the spirit thereof as defined by the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States, is

1. An automatic signaling system for a street intersection having a traffic signal for indicating stop and g0, switching means for operatingsaid signal, driving means for moving said switching means through a signal cycle, said driving means comprising energizable windings retardation of the driving means;

2'. In a trafiic signal :forregulating the flow of traiiic at intersection of :streets, in combination, a'trafli'c signal, switching means capable of controlling said trafl'lc signal, a motor for said 7 switching 'means, said motor having a forward driving and a reversing winding energizable simultaneously introduce the forward speed of the motor caused by energization only of the forward driving winding, an energy source, means for associating :said energy source with said forward driving and reversing windings, and trafiic actuablemeans for operating said last named means.

73. In a traffic signal capable of operating through 'arsignal cycle for regulating the flow of trafiic at a street intersection, a traflic signal,

switching means capable of controlling said' trafiicrsignal, amotor for operating said switchingrmeans, said motor having a driving winding for-pausing'rotation of the motor in one direction 'and'a reversing winding simultaneously energizable with the driving winding to produce a torque in the opposite direction to reduce the forward speed of the motor caused -by energizetion.v of the driving winding only, an energy source, means for connecting said energy source with said driving and reversing "windings, and traffic actuablelmeans for initiating operation of the signal :cycle.

4. A=traffic signal capable of operating through a signal rcycle for regulating the 'flow of traffic at intersecting streets, in combinatioma traffic signal for indicating stop" and go, switching means for causing operation of said'trafiic signal, speed control means foroperating said switching means, .said speed control means having a plu rality'of windings certain of which are capable of producing a torque in a direction of rotation opposite to certain of said other windings to produce a retarding efiect upon said speed control means, and trafiic actuable means for initiating the signal cycle.

5. A traific signal for regulating the fiow'of trailic for intersecting streets, a trafiic signal, switching means connected to said trafiic signal to-cause operation thereof through a signal cycle, control means foroperating said switching means which control means have windings capable of simultaneously producing opposing torques to retardtheforward motion of said control means,

and traffic eactuable means for initiating the signal cycle.

PAUL I". HORNI. 

